This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Introduction: Eye contact is a fundamental component of human social behavior. Individuals with fragile X syndrome, particularly males, avoid eye contact and display other social deficits. To date, this behavior in fragile X syndrome has only been studied in females who show lesser degrees of gaze aversion. Specific Aims: To determine the neural correlates of the perception of direct eye gaze in adolescent males with fragile X syndrome using functional magnetic resonance imaging. Methods: Participants: 13 adolescent males with fragile X syndrome, 10 developmentally-delayed and 13 typically-developing controls Main Outcome Measures: Behavioral performance and brain activation during functional magnetic resonance imaging were evaluated during the presentation of faces with eye-gaze directed to or averted away from subjects. Whole-brain and gaze-related regions-of-interest analyses and regression analyses with task performance were performed.